The present invention relates to a method of and a device for forming an additional stream of air in the guiding comb of an air jet weaving loop for supporting the weft thread during its insertion into an air jet loom.
For air jet looms having a reed space larger than 200 cm there is used an active guide comb also called an active confusor, i.e. the guide comb is equipped with a device for forming an additional stream of air. Such a device for forming an additional stream of air is generally equipped with a system of additional timed nozzles, which are mounted at predetermined distances along the whole length of the guide comb and support the main stream of air thus carrying the weft thread through the opened shed. These additional timed nozzles are usually located in a plurality of special lamellas disposed in the guide comb, pressurized air is supplied through the air vents formed in these lamellas.
The disadvantage of such known arrangements for forming the additional stream of air lies especially in the necessity for making the nozzle diameters and air vents formed by the lamellas very small. Consequently, the manufacture of these parts is very laborious and too costly. Last but not least, there exists the problem that such an arrangement of nozzles is sensitive to contamination, as even small particles of impurities can disturb the correct function of the additional nozzles. From the point of view of economics, the air consumption is also costly. Moreover, the resistance of the tubing to air conductance is high and the air pressure losses are therefore considerable.